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Yuki 3135 hairspring


Dawagner

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Hey RWG does anyone have some good photos of a yuki balance wheel and hairspring preferably detached from the cock? I'm trying to diagnose a possible hairspring issue and want to double check the geometry of mine vs a known working one. Thanks!

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What's wrong


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Not enough swing for the balance wheel. It fluctuates from very fast to very slow in s/d.

I am suspicious that someone put the incorrect staff/roller jewel onto it as it doesn't look original (to the yuki) may be the actual rolex roller jewel assembly.

Also the hairspring was bent at the stud so I straightened that out so it is 90° to where it enters.

I'll post a photo/video when I get home.
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50 minutes ago, Dawagner said:

Ok here's a couple photos. It looks to me like the unlocking jewel assemblys (forget the actual name) were swapped.

Also the hairspring on the yuki has a kink about 1/3 around from the stud is this normal?

cc5181d5a070c23c623fb268e58a0bdf.jpg

f91e53cef1fa67ab7248214d65a0c4e8.jpg

Yes that is normal, That part of the hairspring is called the  terminal curve, that moves the portion of the hairspring towards the end away from the rest of the hairspring and that makes room for the fine adjusting regulator cock to advance or retreat, The hairspring goes through the fine adjusting regulator in what is called the index pins.

 

http://raulhorology.com/2012/12/the-mark-of-a-true-watchmaker-forming-hairsprings-part-4-pinning-to-the-stud-final-adjustments/ 

Edited by Accutronitis
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Yes that is normal, That part of the hairspring is called the  terminal curve, that moves the portion of the hairspring towards the end away from the rest of the hairspring and that makes room for the fine adjusting regulator cock to advance or retreat, The hairspring goes through the fine adjusting regulator in what is called the index pins....
 
http://raulhorology.com/2012/12/the-mark-of-a-true-watchmaker-forming-hairsprings-part-4-pinning-to-the-stud-final-adjustments/ 


Thank you Sir! I figured the it was as it looked too perfect and purposeful but I wasn't able to find any other photos of a yuki hairspring alone so I wanted to check.
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25 minutes ago, Dawagner said:

 

 


Thank you Sir! I figured the it was as it looked too perfect and purposeful but I wasn't able to find any other photos of a yuki hairspring alone so I wanted to check.

 

The hairspring should be flat and run parallel to the balance wheel, As a test of a good terminal curve you should advance the fine adjusting regulator all the way to where the terminal curve starts and the move it all the way towards the to the end of the hairspring and carefully watch the hairspring as you do so, if the hair spring moves around as if being push one way or the other your hair spring has a problem.....

There is one thing I see wrong on yours is at the end of the terminal curve, just before the end the hairspring should make a sharp 45 degree bend outwards to the pin and that 2nd bend should look like the 1st bend where the terminal curve starts, Yours does not, it looks like it just sort of tapers out towards the pin, The pin that holds the end of the hairspring is outside of the circle of the hairspring so that's why the hairspring must be bent to go out and meet that pin, if that makes sense.....

 

 f91e53cef1fa67ab7248214d65a0c4e8.jpg

 

The hairspring should look like this at the end, see how the 1st and 2nd bends look the same ? That is what you want to see.......

 

mark12-2.reg.schematic.numbered.jpg

Edited by Accutronitis
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The hairspring should be flat and run parallel to the balance wheel, As a test of a good terminal curve you should advance the fine adjusting regulator all the way to where the terminal curve starts and the move it all the way towards the to the end of the hairspring and carefully watch the hairspring as you do so, if the hair spring moves around as if being push one way or the other your hair spring has a problem.....
There is one thing I see wrong on yours is at the end of the terminal curve, just before the end the hairspring should make a sharp 45 degree bend outwards to the pin and that 2nd bend should look like the 1st bend where the terminal curve starts, Yours does not, it looks like it just sort of tapers out towards the pin, The pin that holds the end of the hairspring is outside of the circle of the hairspring so that's why the hairspring must be bent to go out and meet that pin, if that makes sense.....
 
 f91e53cef1fa67ab7248214d65a0c4e8.jpg
 
The hairspring should look like this at the end, see how the 1st and 2nd bends look the same ? That is what you want to see.......
 
mark12-2.reg.schematic.numbered.jpg

This is the kind of expertise that is very welcome in the community.


I tread softly along the fine line separating raving insanity and lucid moments of ingenuity. The issue is I've no idea which is which mostly.
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I don't see anything wrong with your hairspring, the coils are concentric and in the round. Look at the hairspring from the side (horizontal) it should be absolutely flat.

The only reason there would be a issue with the roller jewel is if it's been tampered with. If it hasn't leave it be.

 

To diagnose problems with low amplitude, you have to start right at the beginning with the mainspring and barrel. Is it old? Has it been changed?

Once you know the mainspring is supplying adequate power, you move to the gear train. You need to check it is running completely freely.

Remove the hairspring and pallets (power removed!) apply a little power to the mainspring and watch the gear train, it should spin freely and when it reaches the end of the power from the mainspring, slightly reverse spin. Once this is ok, install the pallets and wind the watch a few turns.

Now you check that the pallets are locking, unlocking and return to banking.

To do this gently nudge the pallets, they should cleanly 'flick' to the opposite banking pin and hold tight against the banking pin. Now do it in the other direction and you should see the same. Now give a tiny nudge to the pallets, just enough for them to move a fraction from the banking pin & then be drawn back to the banking pin. Do this several times on both sides of the banking pins. If ok remove pallets (let power down first!) install balance assembly and gently rotate the movement dial up, dial down & dial vertical. the balance should rotate for 15-20 seconds before stopping (slightly less dial vertical) 

 

Once all these tests have been performed you can move onto dealing with hairspring problems & roller jewels ;) 

 

If you diagnose a problem at any of these stages, let us know and we can work from there :) 

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Ok I went through your list with the following findings
1) I swapped out the mainspring barrel and arbor with a gen one in good condition and still had the same issues.
2) the train of gears were not perfect free spinning so I disassembled and cleaned everything again making sure to peg every jewel. After reassembly all the gear train spins freely and even get the slight reverse spin of the escape wheel at the end of the mainspring power.
3) checked the pallet locking and unlocking under powder. The pallet flicks nicely and holds tight against the opposite pin when nudged modestly. When only slightly nudged it will be drawn back up against the pin as well.

Now the issue is with the balance. I removed the power and the pallet. With just the balance installed the balance will rotate freely in all positions except for dial down (balance up) in this position I only get 1 to 3 oscillations before it stops. This is also seen when I reinstalled the pallets the movement will run nicely when it is vertical or with the dial side up (balance down) but will stall and stop when I place it dial side down/balance up.

What does this indicate? Obviously something is rubbing or not freely spinning when the balance is facing up that is resolved in all other positions.

Issues with the balance pivot jewels? Maybe need to be pressed in further?
Roller jewel assembly not seated properly?

Let me know. Thanks!

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If it runs fine in some positions, it's not the roller jewel. 

 

Probable causes are, cracked shock jewel, bent balance staff pivot or shock jewels not installed correctly.

 

Start with the upper and lower shock jewels. Remove them, rinse them in lighter fuel, renata essence or one dip etc. They should separate in to 2 pieces. Remove them from the fluid and place on tissue paper.

Ensure the domed side of the cap (there is a flat and domed side) jewel is facing up, put your index finger on top of it and polish on the tissue paper.

Now flip it over and inspect it with a loupe, it should be a like a mirror. Any imperfections and it's toast. Replace it.

If it's ok, place a circle of Moebius 9010 in the centre, covering 2/3rds of the circumference. Now take the shock jewel and carefully place it on top of the cap jewel. Capillary action should suck the 2 halves together.

If you smear it...Start again!

Once you have done this, reinstall the shock jewels. see what the actions like then. If it's still no good, swap the shock jewel assembles on the top and bottom. Not sure about these but on some movements the cap jewels are different thickness.

Once this has been done and you know the shock jewels are free from cracks and imperfections and cleaned and lubricated we can move on.

 

Dial down carefully inspect the hairspring from the side (horizontal) whilst mounted in the movement. Ensure it is not touching or brushing anything during its rotation. Look really, really carefully. See if there's any noticeable wobble in the balance wheel.

 

Let us know how you get on :) 

 

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